Conventionally, a receptacle outlet includes blade receivers which hold plug blades of a plug therebetween to become electrically conductive with the plug, thereby supplying electric power to the plug (JP-A-2011-198745 A and JP-A-2011-198751).
FIGS. 14A and 14B illustrate a receptacle outlet A2 having a conventional blade receiving structure and a plug B2. Referring to FIG. 14A, the plug B2 includes a plug body 200 to be used by a user for gripping the plug B2, a pair of power-supply plug blades 201 which protrude forward from a leading end face 200A of the plug body 200 (only one of them is illustrated) and a grounding plug blade 203. The grounding plug blade 203 protrudes further forward than the power-supply plug blades 201.
The receptacle outlet A2 includes a receptacle main body 300 having a recessed portion 301 into which a leading end portion of the plug B2 is inserted. On a bottom face 301A of the recessed portion 301, there are installed a power-supply insertion hole 302 into which the power-supply plug blade 201 is inserted in a detachable manner and a grounding insertion hole 303 into which the grounding plug blade 203 is inserted in a detachable manner.
As illustrated in FIG. 14B, inside the receptacle main body 300 there is housed a power-supply blade receiving portion 304 which has a pair of conductive blade springs 305 for retaining and holding therebetween the power-supply plug blade 201 which is inserted into the receptacle main body 300 through the power-supply insertion hole 302. Inside the receptacle main body 300, there is also housed a grounding blade receiving portion 306 which has a pair of conductive blade springs 307 for retaining and holding therebetween the grounding plug blade 203 which is inserted into the receptacle main body 300 through the grounding insertion hole 303.
When the plug B2 is inserted into the receptacle outlet A2, for the purpose of preventing electric shock, first, the grounding plug blade 203 which has protruded further forward than the power-supply plug blade 201 is brought into contact with the grounding blade receiving portion 306. Next, the grounding plug blade 203 is retained by the grounding blade receiving portion 306 and, then, the power-supply plug blade 201 is retained by the power-supply blade receiving portion 304.